The present invention relates to a withdrawal spike for withdrawing medical liquids from containers.
A withdrawal spike, as is e. g. described in the patent DE 38 20 204 C2, comprises a piercing thorn having a ventilation duct and a fluid duct. The piercing thorn is connected with a gripping portion on which a connecting piece connected with the fluid duct is arranged. When the withdrawal spike is used, the piercing thorn penetrates through the elastomeric stopper of a bottle or any other container. Then a syringe or a hose line is connected to said connecting piece. The fluid container can be suspended upside down such that, during the withdrawal process, fluid may flow out of and air may enter the container. The withdrawal spike is further suitable for supplying fluid to the container.
The company B. Braun Melsungen AG, Germany, sells a withdrawal spike under the tradename Mini-Spike Plus. The connecting piece of said withdrawal spike is surrounded by a protective jacket which comprises a hinged cover. The closable protective jacket serves, on the one hand, as protection against contamination of the connecting piece, and prevents, on the other hand, uncontrolled leakage of fluid into the surroundings.
When heparin is withdrawn, all heparin syringes of the entire hospital ward are normally drawn up at a time. The piercing thorn is inserted into a heparin bottle and the latter is placed upside down for withdrawal purposes. The syringes placed in readiness, which have been taken out of their sterile packing, are successively connected to the connecting piece of the withdrawal spike and placed into the respective syringe packing after the withdrawal. During exchange of the syringes to be connected to the connecting piece of the withdrawal spike, the person drawing up the syringes continues to hold the bottle in the hand in an upside down manner. If the syringes are not exchanged very rapidly, heparin may drip from the open connecting piece and contaminate the surroundings.
In the case of cytostatic agents, which are toxic, the personnel always fears that the already opened bottles may fall over and become leaky. Therefore such bottles are frequently seal-welded into a PE-bag. The hinged cover of the Mini-Spike Plus spike is generally considered tight and safe.
In some countries it is common practice to use withdrawal spikes in conjunction with bags, i. e. a perfusor syringe is filled with the contents of a bag. This involves the danger of dripping.
It is an object of the present invention to provide a withdrawal spike offering a maximum of tightness and application reliability and a high degree of cleanliness, hygiene and comfort.
According to the present invention the connecting piece comprises a self-closing valve which is opened by insertion of a tube into the connecting piece. This reliably prevents dripping. In the valve according to the present invention the function of the protective jacket is essentially limited to the prevention of a contact contamination of the connecting piece. Protection against the leakage of fluid is offered by the valve which is in the open position only when a tubular object is pressed into the connecting piece.
Valves, which are opened by insertion of a tubular object, are known in the medical field, mainly for use in conjunction with hose connections, such as catheter connections.
According to the present invention a self-closing valve is integrated in the connecting piece of a withdrawal spike. This causes only a negligible additional expenditure which however offers considerable advantages with regard to application. For example, the exchange of syringes while drawing up heparin syringes is substantially facilitated. In the case of cytostatic agents the danger of the personnel coming in contact with toxic fluids is minimized. Further, the present invention offers advantages with respect to withdrawal of fluids from bags during which process the danger of uncontrolled leakage of fluid is particularly large. The fluid seal does not become effective only at the outlet of the connecting piece but already at its inlet such that the inner wall of the connecting piece is also protected against contamination.